UHD/4K wo/HDR

[kfbkfb]

I don't know of any cases where a movie is rescanned for a UHD/4K Blu-ray release but doesn't have (some form of) HDR.

Older movies don't have "HDR" content, if a company such as Criterion rescans and releases older movies for UHD/4K Blu-ray release, should they add (fake) HDR or not?


Kirk Bayne

[unberechenbar]

The Good, the Bad and the Ugly UHD release doesn't have HDR. One of the releases of Suspiria is also lacking HDR, as is the Italian release of Dawn of the Dead. A few newer movies have also been released on UHD without HDR, like The Outpost.

I'm not sure what you mean by the term fake HDR. Usually it is used when a release is touted as having HDR but doesn't get much brighter than SDR, like with Blade Runner 2049. HDR has added a lot to some old releases like My Fair Lady and Lawrence of Arabia and black-and-white films like Doctor Strangelove, so it doesn't really matter how old a movie is; it can still benefit from the application of HDR.

[kfbkfb]

Fake HDR:
Created solely in post production, IMHO, it's a step away from restoration toward enhancement.

I would prefer that older movies be restored only (dirt and scratches removed, colors restored, reasonable amount of NR applied to the soundtrack).


Kirk Bayne

[nissling]

Originally Posted by kfbkfb

Fake HDR:
Created solely in post production, IMHO, it's a step away from restoration toward enhancement.

Essentially all HDR is added in post.

Utilizing HDR is not just about having a greater dynamic range and larger color gamut than BT.709, but more so to advance from the power law EOTF that have plauged the film industry for so many years. The tone curve is only correct when using a reference grade CRT monitor (i.e. Sony BVMs) and all other display technologies essentially emulate how a CRT behaves. With a PQ tone curve, the luminance level is absolute and can be reproduced much more accurately across various displays.

BT.709 is technically speaking not capable of reproducing the dynamic range of a projected 35mm print. Negative film also have very good dynamic range - you can often overexpose 4-5 steps without losing detail in highlights - and it's a missed opportunity to limit yourself to SDR in those cases. The Good, The Bad, The Ugly was an expection probably due to the restoration being completed in SDR. Not opting for HDR in that case can be understandable but we'll probably see an upgrade at some point.

Even if you're conservative in your color timing, which is sane when working with archive films in general, you can still benefit greatly from HDR.

[kfbkfb]

HDR done (all or mostly) in post production raises the issue of a rerelease of a movie title with different/more HDR (perhaps supervised/approved by the director of the movie).

I don't know if current or planned image recorders will capture "brighter than white" in the original scene, if so, HDR would then make sense, otherwise, I see HDR (only the brighter than white part) as a marketing gimmick.


Kirk Bayne

[nissling]

I think you're missing the point of HDR. Like I mentioned before, you finally get rid of power law EOTF and BT.709. We've all been stuck to CRT standards for many years, dating back to the 1930s. There's nothing to lose going over to HDR.

Most films are shot digitally in LOG, rather than linear or power law. Film is often scanned in linear with at least 12 bits color depth. As mentioned earlier, recreating the highlights that negative film can capture requires major compromises when doing grading in SDR. Even if you limit your peak to around 300 or 400 nits it can really help to avoid clipping without sacrificing APL.

One thing tho I will say is that HDR shouldn't be used as a light cannon on catalog titles. Or as a light cannon all together for that matter. That would basically bring a visual kind of loudness war to the film industry but from what I've seen those cases are more exceptions rather than rules thankfully. When HDR in Windows and macOS is at the same level as on UHD-BD, I don't think anyone is stupid enough to display an Excel or Word document at 1000 nits.